| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an annular member, when being used as a member for an image forming apparatus, suppressing concentration irregularity. <P>SOLUTION: The annular member includes a core body, and an elastic layer provided on the core body and comprising vulcanizate of rubber compositions including polysulfide polymer represented by the following (A), and an elastic material represented by the following (B). (A) Polysulfide polymer has at least one structural unit selected from "-(C<SB POS="POST">2</SB>H<SB POS="POST">4</SB>OCH<SB POS="POST">2</SB>OC<SB POS="POST">2</SB>H<SB POS="POST">4</SB>-S<SB POS="POST">x</SB>)-" and "-(CH<SB POS="POST">2</SB>CH(OH)CH<SB POS="POST">2</SB>-S<SB POS="POST">x</SB>)-", (where, x is an integer not less than 1 and not more than 5) and has at least one of thiol group represented by "-C<SB POS="POST">2</SB>H<SB POS="POST">4</SB>OCH<SB POS="POST">2</SB>OC<SB POS="POST">2</SB>H<SB POS="POST">4</SB>-SH" and "-CH<SB POS="POST">2</SB>CH(OH)CH<SB POS="POST">2</SB>-SH" at the terminal. (B) The elastic material other than the polysulfide polymer, has at least double bond in the chemical structure. <P>COPYRIGHT: (C)2012,JPO&INPIT |
